/**
 * Copyright (c) 2011-2017, James Zhan 詹波 (jfinal@126.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.jfinal.core;

import java.lang.reflect.Method;
import java.util.Map;
import java.util.Map.Entry;
import javax.servlet.http.HttpServletRequest;
import com.jfinal.core.converter.TypeConverter;
import com.jfinal.kit.StrKit;
import com.jfinal.plugin.activerecord.ActiveRecordException;
import com.jfinal.plugin.activerecord.Model;
import com.jfinal.plugin.activerecord.Table;
import com.jfinal.plugin.activerecord.TableMapping;

/**
 * Injector.
 */
public class Injector {
	
	private static <T> T createInstance(Class<T> objClass) {
		
		try {
			return objClass.newInstance();
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
		
	}
	
	public static <T> T injectModel(Class<T> modelClass, HttpServletRequest request, boolean skipConvertError) {
		String modelName = modelClass.getSimpleName();
		return (T)injectModel(modelClass, StrKit.firstCharToLowerCase(modelName), request, skipConvertError);
	}
	
	public static <T> T injectBean(Class<T> beanClass, HttpServletRequest request, boolean skipConvertError) {
		String beanName = beanClass.getSimpleName();
		return (T)injectBean(beanClass, StrKit.firstCharToLowerCase(beanName), request, skipConvertError);
	}
	
	@SuppressWarnings("unchecked")
	public static final <T> T injectBean(Class<T> beanClass, String beanName, HttpServletRequest request, boolean skipConvertError) {
		
		Object bean = createInstance( beanClass );
		String modelNameAndDot = StrKit.notBlank( beanName ) ? beanName + "." : null;
		
		TypeConverter converter = TypeConverter.me();
		Map<String, String[]> parasMap = request.getParameterMap();
		
		Method[] methods = beanClass.getMethods();
		for ( Method method : methods ) {
			
			String methodName = method.getName();
			if ( methodName.startsWith( "set" ) == false || methodName.length() <= 3 ) {  // only setter method
				continue;
			}
			
			Class<?>[] types = method.getParameterTypes();
			if ( types.length != 1 ) {  // only one parameter
				continue;
			}
			
			String attrName = StrKit.firstCharToLowerCase( methodName.substring( 3 ) );
			String paraName = modelNameAndDot != null ? modelNameAndDot + attrName : attrName;
			
			if ( parasMap.containsKey( paraName ) ) {
				
				try {
					
					String paraValue = request.getParameter( paraName );
					Object value = paraValue != null ? converter.convert( types[0], paraValue ) : null;
					
					method.invoke( bean, value );
				} catch (Exception e) {
					if (skipConvertError == false) {
						throw new RuntimeException(e);
					}
				}
				
			}
			
		}
		
		return (T)bean;
	}
	
	@SuppressWarnings("unchecked")
	public static final <T> T injectModel(Class<T> modelClass, String modelName, HttpServletRequest request, boolean skipConvertError) {
		
		Object temp = createInstance( modelClass );
		if ( temp instanceof Model == false ) {
			throw new IllegalArgumentException( "getModel only support class of Model, using getBean for other class." );
		}
		
		Model<?> model = (Model<?>)temp;
		Table table = TableMapping.me().getTable( model.getClass() );
		
		if ( table == null ) {
			throw new ActiveRecordException( "The Table mapping of model: " + modelClass.getName() + 
					" not exists or the ActiveRecordPlugin not start." );
		}
		
		String modelNameAndDot = StrKit.notBlank( modelName ) ? modelName + "." : null;
		Map<String, String[]> parasMap = request.getParameterMap();
		TypeConverter converter = TypeConverter.me();
		
		// 对 paraMap进行遍历而不是对table.getColumnTypeMapEntrySet()进行遍历，以便支持 CaseInsensitiveContainerFactory
		// 以及支持界面的 attrName有误时可以感知并抛出异常避免出错
		for ( Entry<String, String[]> entry : parasMap.entrySet() ) {
			
			String paraName = entry.getKey();
			String attrName;
			
			if ( modelNameAndDot != null ) {
				
				if ( paraName.startsWith( modelNameAndDot ) ) {
					attrName = paraName.substring( modelNameAndDot.length() );
				} else {
					continue ;
				}
				
			} else {
				attrName = paraName;
			}
			
			Class<?> colType = table.getColumnType( attrName );
			if ( colType == null ) {
				
				if ( skipConvertError ) {
					continue ;
				} else {
					throw new ActiveRecordException( "The model attribute " + attrName + " is not exists." );
				}
				
			}
			
			try {
				String[] paraValueArray = entry.getValue();
				String paraValue = ( paraValueArray != null && paraValueArray.length > 0 ) ? paraValueArray[0] : null;
				
				Object value = paraValue != null ? converter.convert( colType, paraValue ) : null;
				model.set( attrName, value );
			} catch (Exception e) {
				
				if ( skipConvertError == false ) {
					throw new RuntimeException( "Can not convert parameter: " + paraName, e );
				}
				
			}
		}
		
		return (T)model;
	}
}

